1. Field of the Invention
This invention relates to a method and system for computer analysis of body sounds derived from the muscular activity of various body organs or systems, and to use of such method and system in diagnosing and monitoring activity of diseases and syndromes associated with abnormal sound production.
2. Description of the Prior Art
The stethoscope has been used for evaluation of human disease since the 18th Century. Auscultation is performed by placing the stethoscope on the skin overlying human structures such as heart, abdomen, lungs, or blood vessels, and allows the physician to hear body sounds in the frequency range of human hearing. However, the stethoscope does not allow evaluation of sounds in the low frequency range not heard by the human ear ("infrasound"), and only permits real-time, audible evaluation of body sounds.
Phonocardiography is an established technique for converting heart sounds within the auditory range into electrical energy using a microphone, followed by oscilloscopic or paper visual display of heart sounds within the time domain. Apex cardiography is also an established technique somewhat similar to phonocardiography except that it deals with low frequency vibrations in the infrasonic range. Some physicians or trained personnel have performed limited evaluation of computer processing of heart sound data (phonocardiography and apex cardiography) as described, for example, in "Computer Analysis Techniques for Phonocardiogram Diagnosis" published in "Computers and Biomedical Research", by Sarkady A. A. Clark R. L. and Williams R, 9, 349-363, 1976 or in "Recording of the Fourth Heart Sound by the Signal Averaging Method", by Yanaga et al, Jap. Heart J., May 1977, 340-347. However, these techniques have not been utilized for evaluation of the diagnostic utility of abnormal sound generation in other body systems, such as evaluation of abnormal bowel sounds.